(1) Field of the Invention:
The present invention relates to a magneto-infrared-emitting diode or an infrared laser diode, particularly being operated satisfactorily at the room temperature.
(2) Description of the Prior Art:
The infrared emission having a wavelength ranging from 2 to 15 .mu.m is widely utilized in the industries, particularly in the military use. The conventional principle of the operation of the light-emitting diode or the solid-state laser diode operating at the above wavelengths is based on the recombination radiation of excess electrons and holes, whose concentrations deviate remarkably from the thermal equilibrium values, injected in a narrow-gap semiconductor, such as InSb, by passing high current to the p-n junction formed on the semiconductor.
Concretely speaking, as shown in FIG. 1, a p-n junction 1 is formed at a central portion of a semiconductor plate consisting of, for instance, InSb by diffusing p-type and n-type impurities respectively into both end portions of the semiconductor plate. In a situation where the above semiconductor plate is refrigerated at temperatures as low as 77.degree. K. by liquid nitrogen, the radiation 5 having a wavelength of middle-infrared (from 2 to 15 .mu.m), which is emitted from a surface of the semiconductor plate by the recombination of excess electrons 3 and excess holes 4 injected into the p-n junction 1, can be obtained.
However, generally speaking, a relation expressed by the following equation can be found between the wavelength .lambda. .mu.m of the light emitted by the recombination of pairs of electron-holes and the energy gap Eg eV of the semiconductor in which the recombination of those pairs is taking place; EQU .lambda.(.mu.m)=1.24/Eg (eV).
So that, a narrow energy gap, which does not exceed substantially 0.6 eV, e.g., 0.18 eV for InSb semiconductor, is required for the semiconductors to obtain the infrared emission of wavelengths from 2 to 15 .mu.m. Besides, in order to keep the extrinsic p-type and n-type properties in such narrow-gap semiconductors, it is also required to refrigerate them at temperatures as low as 77.degree. K. by the use of liquid nitrogen. Whilst, at room temperature, the extrinsic narrow-gap semiconductors, which have p-n junction at lower temperatures, revert immediately to the intrinsic state, so that the recombinations radiation could scarely be expected.
Accordingly, the conventional infrared-emitting diode or the conventional infrared laser diode, in which the recombination radiation of pairs of electron-holes at the p-n junction is utilized, has such serious defects for practical use as required to be operated in the situation where those diodes are refrigerated at extremely low temperatures in a dewar filled with liquid nitrogen and the like, and hence the structure of the emitting apparatus is complicated, expensive, and moreover extremely inconvenient for handling.